This proposal plans for the acquisition for an Affymetrix GeneChip Expression Analysis System (quoted at $149,950). This system includes a scanner and fluidics station for reading data collected on a high density DNA array (GeneChip) as well as software and computer to run the scanner. We are also requesting funds for an additional computer and software package ($12,500) for a data analysis workstation which will be solely dedicated to researchers using the GeneChip Expression Analysis System. This equipment will provide a means by which global regulation of gene expression can be accomplished n the entire E. coli genome. We additionally request $25,000 to purchase 100 GeneChips which will be used by all researchers-participating in this proposal as outlined in the table "Anticipated Usage of Requested Accessories". The proposal will provide instrumentation for rapid, quantitative analysis for global gene expression systems and a variety of other basic research projects which address genome level analysis. This equipment will be of use to ongoing research in a variety of laboratories at the University of Wisconsin- Madison.